Re: [pmacct-discussion] Source port column name depends on database
On 09/15/2010 05:48:51 AM, Paolo Lucente wrote: > Hi Chris, > > On Tue, Sep 14, 2010 at 09:16:37AM +0200, Chris Wilson wrote: > > > I'm not sure about adding a new config switch, do we actually need > it? I > > seem to recall some wiser counsel to not add configuration options > where > > possible, as it exponentially multiplies the complexity of the > software > > code and also linearly increases the complexity of using it. > > > > If our intention is to rename the MySQL fields going forward, why > not just > > use a new schema version to grandfather the old column names? > > Funnily enough, and that was my perspective, in this case a > configuration > switch only adds two if-then-else in the common SQL plugins code. > Whereas > impact of a new schema version you can verify it yourself by grepping > the > source code for 'sql_table_version'. But saving a config switch, i > agree, > it's always nice. I'd target release 0.12.5 for this as 0.12.4 is > planned > to be out soon (by end of the month). Will give a shout as soon as i > get > something workable in the CVS. I too don't like having a config switch. But note that changing the schema in this fashion breaks backwards compatibility in anything that's querying the data. So, I have thoughts. Mostly on version numbering schemes. Feel free to ignore this. I've not given it a whole lot of thought regards pmacct. Breaking backwards compatibility is ok in software under development, pre version 1.0. After that I like seeing the major version number bumped when there's a backwards incompatible change (e.g. 1.0 -> 2.0). The friendly way to proceed is to announce the upcoming change and introduce a flag to enable the new functionality, with the default to be not-enabled. (--new-feature=off). Eventually the default changes to --new-feature=on and the major version number increments. The next time the major version number increments the flag, --new-feature, is dropped. This is annoying to maintain but should give the end-user enough time to make any changes that there should be no cause for complaint. So, I like the major.minor.bugfix version numbering system, where major is incremented when the user really needs to pay attention or things just won't work. Perhaps the schema version numbering system could also use a policy, so as to be able to distinguish changes that break backwards compatibility? Karl Free Software: "You don't pay back, you pay forward." -- Robert A. Heinlein ___ pmacct-discussion mailing list http://www.pmacct.net/#mailinglists
Re: [pmacct-discussion] Source port column name depends on database
Hi Paolo,
On Wed, 15 Sep 2010, Paolo Lucente wrote:
> On Tue, Sep 14, 2010 at 09:16:37AM +0200, Chris Wilson wrote:
>
> > I'm not sure about adding a new config switch, do we actually need it?
>
> Funnily enough, and that was my perspective, in this case a configuration
> switch only adds two if-then-else in the common SQL plugins code. Whereas
> impact of a new schema version you can verify it yourself by grepping the
> source code for 'sql_table_version'.
I think the code that uses sql_table_version has been well written, and
none of these places should need to be changed at all.
The only place that should need changing, I hope, is the one line of
sql_common.c that currently says:
if (!strcmp(config.type, "mysql") || !strcmp(config.type, "sqlite3")) {
and would now check for sql_table_version <= 7 (or similar) instead.
So this change does not actually increase the code complexity, or the
number of config options, at all.
> I'd target release 0.12.5 for this as 0.12.4 is planned to be out soon
> (by end of the month). Will give a shout as soon as i get something
> workable in the CVS.
That would be great, please do!
Cheers, Chris.
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Re: [pmacct-discussion] Source port column name depends on database
Hi Chris, On Tue, Sep 14, 2010 at 09:16:37AM +0200, Chris Wilson wrote: > I'm not sure about adding a new config switch, do we actually need it? I > seem to recall some wiser counsel to not add configuration options where > possible, as it exponentially multiplies the complexity of the software > code and also linearly increases the complexity of using it. > > If our intention is to rename the MySQL fields going forward, why not just > use a new schema version to grandfather the old column names? Funnily enough, and that was my perspective, in this case a configuration switch only adds two if-then-else in the common SQL plugins code. Whereas impact of a new schema version you can verify it yourself by grepping the source code for 'sql_table_version'. But saving a config switch, i agree, it's always nice. I'd target release 0.12.5 for this as 0.12.4 is planned to be out soon (by end of the month). Will give a shout as soon as i get something workable in the CVS. Cheers, Paolo ___ pmacct-discussion mailing list http://www.pmacct.net/#mailinglists
